In a wireless local area network (WLAN) system, communications between an access point (AP) and a station are performed. The AP provides stations with communication services to in a service range.
A basic configuration block of a WLAN system defined in IEEE 802.11 is a basic service set (BSS). A BSS may include an independent BSS in which user terminals in the BSS perform direct communications with each other, an infrastructure BSS in which an AP is involved in communications between a user terminal and a user terminal inside or outside the BSS, and an extended service set which connects different BSSs to extend a service area.